Hybrid III-V-on-SOI optical spot size converter by self-aligned selective undercut dry etching of Si.

A technology called self-aligned selective undercut dry etching processing has been demonstrated for fabricating a highly efficient hybrid optical spot size converter (SSC) on a Si-on-insulator (SOI) template. The process was based on a bonded wafer between the upper InP-based multiple quantum well heterostructure and the lower SOI substrate. After defining the mask on the upper InP-based ridge waveguide, / dry reactive ion etching was then used for selective undercut etching of the Si material from the surrounding materials, forming a vertical waveguide coupler of the optical SSC.

Taiwanese farm workers' pesticide knowledge, attitudes, behaviors and clothing practices.

The purpose of this study was to assess Taiwanese fruit farm workers' knowledge, attitudes, behaviours, and clothing practices regarding pesticide activities. Seventy-seven fruit farm workers from four districts of Tainan City, Taiwan completed the questionnaire. Results indicated that farmer workers had a good overall level of knowledge of the adverse effects of pesticides on human health and most had experienced symptoms of pesticide poisoning.